Method of preparing films for kinetoscopes



Aug. 7, 1923. 1,463,802

J. S. DAWLEY METHOD OF PREPARING FILMS FOR KINETOSCOPES Filed Sent. 1919 //v VEN 70R Jam smegma/e .B 20% m Patented Aug. 7, 1923.

PATENT OFFICE.

JAMES 8m DAWLEY, 0! NEW YORK, H. Y.

IETHOD OF rmaame FILES FOB KINMOSCOPR.

Application fled leptember 8, 1919. Serial Io. 328,481.

To all whom it may cmwem:

Be it known that I JAMES Susana pawm, a citizen of the Ijnited States residm at New York, in the county of N ew Yor and State of New York, have invented certain Improvements in Methods of Pre ar Films for Kinetoscopes, of which t e f lowing description, in connection with the accompanying drawings, is a specification, like reference characters on the drawings indicating like parts in the several figures.

This invention relates to methods of preparing positive films for use in moving picture projecting machines or kinetoscopes.

It is well known that by first exposing a film to a well illuminated object, for example a stage setting, and then exposingthe film a second time to another object, for instance a person dressed in white, a negative may be ro'duced such that when a positive is ma e from it and promoted the person on which the second exposure was made will appear as a phantom or transparent image in the stage setting on which the first exposure was made.

An object of this invention is to provide a method by which distant and inaccessible laces ma be exhibited on a screen with the iving an moving element added to them and without the necessity of the places being visited either b the moving picture protographer or by t e living or moving element which appears in them as a phantom.

It has heretofore been impossible to produce such phantoms against a white or very 1i ht background, the delineation of the antom being lost in those portions of the Elm which had previously been exposed to white. An ob'ect of this invention is to provide a metho of obtaining a very well delineated phantom against a white background or, in brief, to photograph a white ob'ect on a white object and secure perfect de ineati'on of both.

A further object of the invention is to provide a method by which the objects which are to appear in phantom may be photoraphed against a black background without detracting anything from the excellence and definition of the first picture taken on the film because of the reflection from the black background.

description when read in connection with the accompanying drawings and will be pointed out in the appended claims.

In the drawings- Figure 1 represents a picture to be used in 7 this method;

Fig. 2 represents a negative made from the picture of Fig. 1;

Fig. 3 represents a positive plate made from the negative of Fig. 2;

Fig. 4 represents the step of photographing on a moving film the positive of ig. 3 while illuminating it from the back;

, Fig. 5 represents the step of photographing upon the same film moving persons: and

Fig. 6 represents the picture obtained by projectingia positive of the film obtained as shown in ig. 5.

For the purpose of illustrating the manner in which the method of my invention may be carried out in practice, it will be assumed that it is desired to show upon the screen disembodied s irits of human bein as visitin various istant and wonderful places an buildings upon the earth. Aprint (Fig. 1) or photograph of the selected place is taken, for instance a white marble temple or shrine. This photograph is photographed in the usual manner u n a plate (Fig. 2) or film which may be either larger or smaller than the original picture. The negative thus obtained is placed in direct contact with a sensitive plate or film, exposed and develo d a positive 2 (Fig. 3) being thereby obtained in a manner similar to that in which lantern slides are produced. This ositive 2 is placed in a box 4 with substantiall its entire surface exposed outside the box. in the box lam s 6, 8 are arranged at the two ends of t e picture and opaque plates 10, 12 are arranged so as to intercept any direct rays of lig t from the lamps which might fall upon the positive. The back of the box opposite to the positive has a white surface 14 to reflect the light toward the positive and preferably between the white surface 14 and the positive 2 a diflusing plate 16, which may be of ground glass, is arran d. To furnish the required brilliant lighting it is found that 250-watt tungsten or nitrogen lamps give satisfactory results.

In front of the positive thus illuminated is placed a moving picture camera 20 of usual construction at the proper distance to cause the illuminated positive to cover the rtion of the film exposed at one time. he camera 20 is then operated to ex ilghse the required length of film (Fig. 4). e film is then rewound, care being taken to mark thejilm so that when exposed a second time the area of each second exposure will coincide accurately with the first.

The persons a, b or moving objects which are to appear as spirits or phantoms in the scene already taken are placed in front of a black background 22 which will reflect as little light as fossible, for instance one of black velvet. f ob'ects are be photographed they are pre erably white, and f persons are to appear they are dressed in white, their hair wdered, and the exposed portions of their skins whitened. Extremely powerful illumination is then thrown upon the persons a, b or objects and the film is again exposed by operating the moving picture camera 20, the persons in the meantime acting the part of tourists viewing and enjoying the scenes represented on the positive to which the film has been previously exposed or going through an action appropriate to the background a ready on the film, the object being to cause them to form an integral part of the scene in which they are represented as erforming. If thepersons or objects in white which are being photographed are illuminated by owerful light coming from the front, the ight will also fall upon the black background. When a black surface, no matter how nearly perfect the black ma be, is thus illuminated and hoto aphe it will appear ay. There ore, if such a br1lliantly iluminated black surface is photographed on a film already exposed the contrast and definition of the first picture will be greatly reduced and the icture probably spoiled. To prevent this arrange lights 24, 26, one at each side of the black backund 22, in such a way that pencils of light fall upon the objects arranged 1n front of the background to be photophed but do not fall directly upon background itself, the area covered by the pencils of ligll it bein controlled by dlaphragms 28, 30. refera 1y black wings 32, 34 are arranged to receive and absorb the light which passes the objects, these wings being outside of the field of the photograph. The persons a, b may move about as desired in the field covered by the pencils of light from both the lights 24, 26 and the size of the field may be varied by the distance of the lights from the persons and by the size of the diaphragms 28, 30. The slze of the phantom in proportion to the background is controlled by the distance of the camera from the persons a, b.

The film, having been exposed to the moving persons a, b, is developed and a positive 1,4ea,so2

film made therefrom in the usual manner. When this film is placed in the usual projection apparatus and thrown upon the screen, a picture such as indicated in Fig. 6 will appear, the phantoms a, b being in action a ainst a stationary background and all the etails, both of the background and of the hantoms, being well delineated.

The egree and nature of the light used is very im ortant in obtaining satisfactory results. T e ordinary spotlight arc has only about 300 candle power and such li hts are quie unsuitable for this purpose. atisfactory results are possible only by the use of extremely powerful arcs of special construction. t is believed that are lights similar to those manufactured by the Sperry Gyroscope lights which have carbons of a s ecial composition are the best now availa le. These arcs furnish a light of great actinic power closely approaching sunlight. In fact, the lamp designed and used for this pur ose is known as the sunlight arc. With t ese lamps 100,000 candle power per unit is obtainable with a consumption of current of 100 to 150 amperes at 110 volts, direct current being preferably used. It is found that as the amperage is increased above 100 the amount of light increases out of proportion to the amount of additional current used. This is due to the formation of a luminous .gas in the crater of the negative carbon which gives a very intense light, the light being the closest approach to sunlight, in its spectrum and actinic properties, that is now known. In fact, with such lights it is possible to produce efiects which could not be secured even by the use of direct sunlight. In some cases it may be found desirable to employ parabolic mirrors to concentrate the h ht and by this means candle power of a mi ion or more may be obtained.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. That method of making positive films for use in moving pictlu'e rejection apparatus which consists in brilliantly illuminatin a positive from the back, photographin the positive repeatedly upon a film, rewin 'ng the film, and again ex- Posing the film to brilliantly illuminated ivin and moving objects in white a ainst a su dtantially unilluminated black ackoun . 2. That method-of making positive films and moving objects, and illuminating the wing objects Company for searchlot with so great intensity that both the original picture and the superposed moving picture will a pear in clear delineation.

3. hat method of making positive films for use in movin picture pro ection which consists in selecting a background picture, photographing the picture to obtain a negative, reparing from the ne ative a positive, illuminating the positive from the back and photographing it with it movin picture camera upon the required length 0 film, rewinding the film, indexing the 1m to cause the second exposure to coincide with the first, preparing in white moving objects to appear in the picture, placing them be fore a black background, then re-exposing the film to said objects while illuminating them by powerful lights thrown from the sides upon the objects and not upon the background, the light being far more intense per unit of area than that thrown upon the positive first photographed, and then preparing the positive film in the usual manner.

4. That method of making positive films for use in moving picture projection apparatus which consists in brilliantly illuminating a positive from the back, photoraphing the positive repeatedly upon a m, rewinding the film, again exposing the film to brilliantly illuminated moving ob- 'ects in white against a substantially unllluminated black back round, and then developing the film and printing positives therefrom.

5. That method of making positive films for use in moving picture projection apparatus which comprises preparing a positive of a still white object, illuminating thepositive from the back, photographing the positive repeatedly upon a lm, rewinding the film, again exposing the film to white moving ob ects, and illuminating said objects with reat intensity to cause them to appear in ear delineation.

6. That method of making positive films for use in moving picture pro ection which consists in preparing a transparency from a selected still picture, illuminatin the transparency from the back while p otographing it with a moving picture camera upon the required length of lm, pre aring in white moving objects to appear m t e picture, lacing them before a black! backgroun then re-exposing the film to said objects while illuminatin said objects only and not the backgroun and then preparing a positive fi m in the usual manner.

In testimony whereof I have signed my name to this s ification.

JA S SEARLE DAWLEY. 

